Treatment of textile fiber with water repellency agents



Patented a. 24, 1944 TREATMENT OF TEXTILE FIBER WITH WATER REPELLENCY AGENTS Lucius Collins, George Anton Slowinske, and Joseph Edward Smith, Wilmington, Del., assignors to E. I. du Pont de Nemours & Company,

Wilminl' o in, Del., a corporation of Delaware No Drawing. Application April 29, 1941,

- Serial No. 390,922

Claims.

, heretofore known water-repellency treatments whereby to improve the feel of the resulting fiber. It is a further object to improve the initial degree and the durability of the water-repellency finishes obtained by heretofore known methods.

-Other and further important objects of this inventionv will appear as the description proceeds.

The production of water-repellent efiects on textiles is a rapidly expanding art. The early processes involved application of aluminum soaps, or wax emulsions containing aluminum salts. However, the water-repellent efiects obtained were not durable to commercial laundering and dry cleaning. In recent years it has been found that water-repellent eifects On textiles that are durable to commercial laundering and dry cleaning can be obtained by the application from an aqueous solution of a quaternary compound of the type where It stands for an aliphatic hydrocarbon radical of 9 to 2'7 carbon atoms, N(tert) stands for the molecule of a tertiary aliphatic or heterocyclic base such as trimethylamine, pyridine, C-alkyl pyridine and quinoline, and It stands for the anion of a salt forming acid. 7

A typical member of the above group of compounds is stearamido-methyl-pyridinium chloride, whose preparation is described in detail in U. 8. Patent No. 2,148,392 toBaldwin and Walker. Other water-repellency agents suggested'in the art for giving durable, laundry-fast finishes are quaternary ammonium compounds, thiouronium c mpounds, phosphonium compounds, methylol ethers, containing in their structure an alkyl chain of 9 to 27 carbon atoms and expressible by the general formula A-CHe-Z, wherein A is a radical free from water-solubilizing groups but containing the mentioned alkyl chain and attached to the CH2 group through a non-carbonic atom such as O, S or N, while Z is a solubilizing radical likewise attached to the CH2 group through a non-carbonic atom. Further details on the nature of this group of applicable agents and illustrations thereof are given hereinbelow.

The special group where the member 2 endows the compound with solubility in water, is also discussed at length in copending application of Osborn C. Bacon, Serial No. 336,375 (Patent No. 2,327,160, issued August 17, 1943).

In general, the process of treating textile fibers with these compounds consists of impregnating the fiber at relatively low temperature, say below 45 C., with an aqueous bath of the above compounds or with an organic solvent solution thereof the fabric is then dried at low temperature (say below 45 C.) and then subjected to a heat treatment known as the "baking" step, in the absence of moisture, until the treating agent undergoes decomposition on the fiber. This treatment is generally efiected at a temperature between 100 and 225 C., for a period ranging inversely with the temperature, from half an hour to a few seconds, and in the case of agents which are pyridinium salts, the odors of pyridine may be detected, evidencing decomposition of the treating agent.

The said water-repellency treatments have been applied to cellulosic fiber such as cotton or viscose rayon, as well as to animal fiber, such as wool or silk, as well as to artificial fiber, for instance nylon, and to leather, and in all cases water-repellency effects are obtained which are more or less permanent in the sense that they Decially cotton, the softness imparted is sometimes more than desirable. The fabric may acquire a raggy feel, and in the case of a woven fabric the slip resistance (that is the power to withstand fraying or separation or the weave) is often materially diminished.

Now according to our present invention, the above defect is materially overcome by incorporating in the treatment bath containing the water-repellency agent a relatively small quantity of a thermoplastic water-insoluble resin, preferably of the vinyl-polymer type, for instance the polymers derived from lower alkyl-esters of acrylic acid and methacrylic acid. Moreover, we have found to our surprise that instead of weakening the water-repellency effect as was to be expected in view of the fact that these resins themselves are readily wetted by water, the initial strength of the water-repellency effect and its resistance to laundering and dry' cleaning are substantially increased. a

The addition of resins to the treatment bath,

according to' this invention is not to be confused with th suggestions in the literature of the prior art of adding to the impregnation bath resinforming materials to produce a urea-formaldehyde resin on the fiber in the baking step. The distinctions are numerous and radical. In the first place, the said prior art added elements adapted to form a resin on the fiber. We propose to add a pre-formed resin, that is a finished polymer. The object of the resin of the art was to impart crease-resistance to the fabric. Our object and achievement is first to stiffen the fabric overcoming its raggy feel, and secondly to enhance the initial value and durability of the water-repellency effect itself. Thirdly, in the joint water-proofing and crease-resisting treatment, the resin-forming agents are present in large concentration relative to the water-repel lency and crease-resistance, resin-forming agents are selected which are water-soluble. Hence, these agents permeate the'fiber throughout and eventually are polymerized therein into a resin. In the process of this invention, the resin employed is initially water-insoluble. Hence, it is incorporated into the aqueous treatment bath in the form of a dispersion, or else thetwo agents are jointly applied from a solution in an organic solvent.

For efiectingthe aforesaid dispersion in theaqueous treatment bath containing the waterrepellency agent, we find that best results are obtained by resorting to positively charged emulsions of the resin. In other words, the resin is to be emulsified by the aid of cation-active dispersing agent, such as a long-chain alkyl quaternary ammonium compound, for instance octadecyl-trimethyl-ammonium bromide; or it may be emulsified by using an electrically neutral, water-soluble, high-molecular-weight protective colloid together with a heavy metal salt or militivalent metal salt and a volatile organic acid. Examples of high molecular weight colloids that are useful are polyvinyl alcohol, natural gums and starches, water-soluble cellulose ethers, and

subjected to-heat up to 200 C. and should not discolor on exposure to artificial light or to sunlight. Resins which are particularly suitable for use inthis invention are polymers and interpolymers of vinyl compounds including styrene, vinyl acetate and esters of acrylic and methacrylic acid. A particularly valuable resin is polymeric n-butylmethacrylate.

The vinyl polymers and interpolymers may be modified by the addition of other resins such as rosin esters and rosin derivatives of low acid number; other natural gums, resins, and their esters; drying oils and semi-drying oils; selected alkyd and modifiedalkyd resins; selected coumarone indene resins: selected phenol aldehyde resins; and dihydronaphthalene resin. The vinyl polymers and mixed polymers may be modified with plasticizers; suitable plasticizers include glycollateesters as butyl phthalyl butyl. glycol- 'late; phosphate esters as tricresyl phosphate.

The modifying resins and plasticizers can be incorporated by dissolving in the monomeric vinyl compounds and polymerizing.

, In carrying out the process of treating textiles, the quaternary compound, for example, is dissolved in water'preferably at.40 to 43 0.. Ethyl alcohol may be used to assist in dissolving the quaternary compound while a buffer such as sodium acetate may be added to prevent tendering in later processing. The concentration of quaternary compound in the bath is adjusted so that from 1.0% to 3.0% is deposited on the goods after impregnation of the textile. The positively charged resin dispersion is added to the bath preferably at 38 to 43 C. The preferred concentration of resin in the bath should be such that 0.1% to 0.3% resin is deposited on the goods after impregnation. Concentrations of resin to give up to 1% resin on the goods may be required in some instances, where a strong bodying effect is desired. The fabric is impregnated in the bath preferably at 32 to 43 C., and

. the fabric dried at a temperature preferably no long-chain ethylene oxide condensation products.

before emulsifying. Resin dispersions prepared by this second method have the advantage of being solvent free. The details of preparing positively charged resin dispersions of vinyl polymers, interpolymers and mixed polymers with other resins are described further in copending applications of J. E. Smith. Serial Nos. 351,083, 351,084, 351,086, 351,087, 351,083 and 351,089 (Patents Nos. 2,343,089, 2,343,090, 2,343,092, 2,343,093, 2,343,094 and 2,343,095, respectively).

As already stated, the resins preferred for this invention are water-insoluble. In addition, they should be such as do not hydrolyze readily in hot alkaline soap solutions and adhere well to textile fabrics. The resins should not discolor when higher than 45 C. It is important to have good air circulation around the fabric; drying temperatures up to C. can be employed if good air circulation is obtained and the temperature on the fabric itself is not higher than 5 45 C. The treated and dried fabric is then cured by heating for 1 to 4 minutes preferably After the baking operation, the fabric is neutralized by a mild wash in a solution of a suitable alkali and a wetting agent. The final rinse removes impurities resulting -from the decomposition of the quaternary compound during the bak in'g step. The rinsed fabric is dried at any convenient temperature. i

The invention is illustrated but not limited by the following examples in whlch parts are by I weight.

Example 1 A positivelycharged aqueous dispersion of jn-butyl methacrylate polymer was prepared as .follows: 25 parts of n-butyl methacrylate monomer. containing 0.25 part of benzoyl peroxide were emulsified by vigorous agitation with 70.9 parts of an aqueous solution containing 2.5 parts .of polyvinyl alcohol, 0.1 part octadecyl trimethyl ammonium bromide and 0.01 part of technical dodecyl diethylcyclohexylamine lorol sulfate. Three and six-tenths parts of a 32% basic aluminum acetate solution and 0.5 part of acetic acid were added while mixing. The emulsiflca- ,tion was carried out at 28 C. The emulsion was heated in a closed glass container in a water bath for 16 hours at 67 C. A stable dispersion of a resin was obtained.

Twenty parts of stearamidomethyl pyridinium chloride were wet thoroughly with 32 parts of ethyl alcohol, and 894 parts of water at 45 C. were added while stirring. Fourteen parts of sodium acetate crystals (NaCaHaOaM-Iz-O) were dissolved in 40 parts of water at 45 C. The solutions were mixed.

Ten parts of the resin dispersion were added to the stearamidomethyl pyridinlum chloride solution to prepare a bath containing 2% stearamidomethyl pyridinium. chloride and 0.25% of n-butyl methacrylate resin. A strip of cotton broadcloth was impregnated in the bath at 43 C. and run between squeeze rolls to obtain a 100% increase in weight. The fabric was dried in a current of air at 32 C. The dried fabric was then heated in an oven at 150 C. for 4 minutes. The fabric was then rinsed for 3 minutes in an aqueous solution containing 0.1% technical sodium lauryl sulfate and 0.1% soda ash. The fabric was given a final rinse in warm water, hydroextracted, and ironed on a mangle.

A second .strip of cotton broadcloth was processed as in the preceding paragraph but omitting the addition of the resin dispersion to the bath.

Tests showed that the first treated fabric (treated with stearamidomethyl pyridiniurn chloride+n-butyl methacrylate polymer) was superior to the second treated fabric in the following respects:

(1) Noticeably better initial water-repellency.

(2) Noticeably better water-repeliency after 5 commercial launderings.

(3) Noticeably better water-repellency after 3 A commercial dry cleanings in Stoddards solvent.

(4) The threads of the fabric were more resistant to slippage.

(5) The tensile greater. 7

(6) The resistance to abrasion was appreciably superior.

(7) The hand was firmer.

Example 2 A positively charged aqueous dispersion. of a n-butyl methacrylate-ester gum mixed polymer was prepared as follows: Twenty-five parts of a n-butyl methacrylate solution containing 12.5

strength was noticeably parts of ester gum and 0.12 part of benzoyl peroxide were emulsified with vigorous agitation with 70.9 parts of an aqueous solution containing 2.5 parts of polyvinyl alcohol and 0.01 part of technical dodecyl diethylcyclohexylamine sulfate. Three and six tenths parts of a 32% basic aluminum acetate solution and 0.5 part of acetic acid Example 1. A second strip of viscose process rayon was treated as above omitting the resin.

The use of the resin with the stearamidomethyl Dyridinium chloride contributed advantages to the treatediabric similar to those obtained in Example 1.

Example 3 A positively charged aqueous dispersion of a methyl methacrylate hydrogenated ester gum mixed polymer, plasticized with di(butoxy-ethyl) phthalate, was prepared. Twenty parts of a methyl methacrylate monomer solution containing 7 parts of hydrogenated ester gum and 2 parts of di(butoxyethy1) phthalate were emulsifled by vigorous agitation with 74.7 parts of an aqueous solution containing 2.5 parts of polyvinyl alcohol and 0.13 part of stearyl trimethyl ammonium bromide. Three and eight tenths parts of a 32% basic aluminum acetate solution and 0.5 part of acetic acid were added while mixing. The emulsiflcation and polymerization were carried out as in Example 1 to obtain a stable aqueous dispersion of a resin.

The resin dispersion was mixed with a stearamidomethyl pyridinium chloride solution in the proportions described in Example 2 and applied to a mixed fabric composed of viscose process rayon and cellulose acetate rayon as in Example 1. A second strip of the fabric was treated, omitting the resin dispersion.

The use of the resin with the stearamidomethyl pyridinium chloride contributed advantages to the treated fabric similar to those obtained in Example 1.

Example 4 A dihydronaphthalene resin was substituted for the hydrogenated ester gum in Example 3. Similar results were obtained. 1

Example 5 Example 6 A tertiary butyl phenol-formaldehyde resin known as Super-Beckacite 1001 was substituted for hydrogenated ester gum in Example 3. Similar results were obtained.

Example 7 A rosin modified alkyd resin known as Amberol 801 was substituted for hydrogenated ester gum in Example 3. Similar results were obtained.

Example 8 A positively charged aqueous dispersion of vinyl acetate polymer plasticized with di(butoxyethy1) phthalate was prepared as follows: Forty parts of a vinyl acetate solution containing 5 parts of di- (butoxy-ethyl) phthalate and 0.2 part of benzoyl peroxide were mixed by high speed agitation with 55 parts of an aqueous solution containing 2.5

parts of polyvinyl alcohol. Four and three tenths,

parts of a 32% basic aluminum acetate solution and 0.? part of acetic acid were added while continuing the agitation. The emulsification was carried out at 30 C. The emulsion was heated in a closed glass container-in a water bath for 16 hours at 50 C. .and 8 hours at 65 C. to obtain a stable aqueous dispersion of a resin. v

I A part of the resin dispersion was mixed with a stearamido-methyl pyridinium chloride solution in the proportions described in Example 1 and applied to cotton poplin as in Example 1.

The results obtained were similar to those described in Example 1.

Example 9 Fifteen parts of n-butyl methacrylate polymer were dissolved in 30 parts of toluene. The solution was emulsified by vigorous agitation at room temperature with 45 parts of an aqueous solution containing 4.5 parts of polyvinyl alcohol (saponiflcation No. 180; viscosity for 4% aqueous solution at C., 40 c. p.)'. Four and three tenths parts of a 32% solution of basic aluminum acetate and 0.7 part of acetic acid were added while continuing .the agitation. A positively charged aqueous dispersion of n-butyl methacrylate polymer was obtained.

Thirty three parts of the resin. dispersion were added .to 1000 parts of a stearamidomethyl pyridinium chloride solution prepared as in Example 1. The mixture was applied to cotton poplin as in Example 1. The results obtained were similar to those described in Example 1.

Example 10 A-resin interpolymer containing methyl methacrylate 38%, isobutyl methacrylate 10%, and

China-wood oil varnish (43%) was substituted for the n-butyl methacrylate polymer in Example 9. Similar results were obtained to those described in Example 1.

Example 11 tained.

The resin dispersion was mixed with a stearamidomethyl pryidinium chloride solution in the proportion described in Example .1 and applied to cotton muslin. A second strip of the-fabric was treated, omitting the resin dispersion.

The use of the resin with the stearamidomethyl pyridinium chloride contributed advantages to the treated fabric similar to those obtained in Example 1.

Example 12 A mixture of 12.5 parts of methyl methacrylate monomer and 12.5 parts of n-butyl methacrylate monomer was substituted for the n-butyl -methacrylate monomer in Exampl 1. Similar results were obtained.

' Example 13 Twenty of methylene-di(stearamidomethyl-thiocyanate) see Example 1 of copending application-.01 Josef Pikl, Serial No. 363,524, Patent No. 2,331,276, issued October 5, 1943); and 8 grams of n-butyl methacrylate polymer were dissolved in 1000 grams of carbon tetrachloride. A strip of cotton jean cloth was impregnated in the bath at 30 C. and run between squeeze rolls to obtain a 100% increase in weight. 'I'he'fabric was,

dried in a current'of air at 30,C. The dried .Quatemary ammonium oxymethyl thiocyanates Ethers of methylol repellency; the hand of the fabric was firm and full.

The following additional examples illustrate further practical procedures for carrying out our invention.

Example 14 Five parts of methylene-bis-stearamidomethyl-pyridinium thiocyanate and 5 parts of butyl methacrylate polymer are dissolved in 1000 parts of a mixed solvent consisting of 667 parts of trichlorethylene and 333 parts of toluene. This solution may be used to impregnate mixed viscose process rayon satin. The excess solution is removed by running the impregnated fabric through squeeze rolls. The solvent is then evaporated at a low temperature and the fabric is heated at 150 C. for 3v minutes. The resulting fabric has a high degree of water repellency and a firm hand. I

Example 15 Methylene-bis-stearamido-methyl-pyridiniumthiocyanate may be substituted for stearamido methyl pyridinium chloride in Example 1. The resulting fabrics are highly water repellent.

It will be understood that our invention is not limited to the precise embodiments set forth in the above examples. Thus, while stearamidomethyl-pyridinium chloride was employed as water repellency agent in most of the above examples, any of the heretofore known water-repiellency agents may be employed for our inven- Among the numerous water-soluble ,types heretofore su gested may be mentioned compounds of the general formula RYCH-.-N(tert)-X, which are'described in more detail in British Patents Nos. 394,196, 466,853, 492,699, 494,761, 501,480, 508,173, and in French Patent No. 848,002. Other water-soluble and organic solvent soluble compounds suitable .for use as the water-repellent component are:

Quatemary ammonium amido methylene thiocyanates;

stearamide (see copending application of Ehgelmann and Pikl, Serial No. 356,356, Patent No. 2,313,741)

Long-chain amido methylene phosphonic acids (copending application of Engelmann and Pikl, Serial No. 322,766, Patent No. 2,304,156);

of the formula RocH,-N-( s ON) i wherein R a long-chain alkyl radical. Additional organic solvent soluble compounds suitable for use as the water repellent component in our invention and expressible by th formula A-CH2--Z as above defined are:

' Long-chain pyridinium sulfltesas described in German Patent No. 662,538 or the correspondlng U. S. Patent No. 2,147,811;

Long-chain thiouronium compounds as described in British Patents Nos. 526,738 and 527,012. The resins for use according to this invention fabric was then heated in an oven at 150 C. for 4 include polymers and interpolymers of vinyl compounds including esters of acrylic and methacrylic acid, acrylamides and methacrylamides,

v acrylonitriles and methacrylonitriles, butadiene,

styrene, vinyl ethers, vinyl esters such as vinyl acetate, and vinyl chloride. The vinyl resins may phthalate, diamyl lactate, butyl phthalyl butyl,

glycollate, tricre'syl phosphate and triethyl citrate. 1

The preferred ratio of resin to water-repellent varies from 0.05:1 to 0.5:1. However, ratios of resin to water-repellent outside the generally preferred'range may be required, particularly when a stiff final finish is desirable.

This invention may be applied to the processing of cotton fabrics, viscose rayon, cellulose acetate, natural silk, wool, nylon, leather and paper, and the advantages of the combined treatment express themselves in the following efiects:

(1) The textiles have superior initial waterrepellency.

(2) The water-repellent finish is more resistant to laundering.

(3) The water-repellent finish is more resistant to commercial dry cleaning.

(4) The finished fabric has better wear resistance.

(5) The threads of the finished fabric are more resistant to slipping.

(6) The tensile strength or the fabric is improved.

(7) The hand and feel of the fabric can be varied widely.

We claim:

1. In the process of treating textile fiber with water-repellency agents of the general formula A-CHa-Z, wherein A is an organic radical free from water-soluhilizing groups but containing at derivatives, the resin being employed in quantity not exceeding 0.5 part by weight for each part of water-repellency agent used.

2. The process of producing upon textile fiber an improved water-repellent finish, which comprises impregnating thesame with an aqueous bath containing a quaternary ammonium compound of the general formula wherein R is an alkyl radical containing from 9 to 27 carbon atoms, N(tert) stands for the molecule of a non-aromatic tertiary base, while X stands for the anion of a water-soluble acid, said aqueous bath containing further a positively charged emulsion of a thermoplastic, water-insoluble, vinyl-polymer type resin, said resin being present in quantity not exceeding 0.5 part by weight for each part of water-repellency agent employed, then drying the fiber and further subjecting the same to dry heat at elevated temperature to develop the water-repellency effect. a

3. The process of producing upon textile fiber an improved water-repellent finish, which comprises impregnating the same with an aqueous bath containing stearaznido-methyl pyridinium chloride and a suspension of a positively charged resin emulsion containing as principal resin the polymer of n-butyl-methacrylate, said resin being present in quantity not exceeding 0.5 part by weight for each part Of water-repellency agent employed, then drying the fiber and further subjecting the same to dry heat at elevated temperature to develop the water-repellency eflect.

4. In the process of surface treatment of cellulosic fabric with stearamido-methyLpyridinium chloride whereby to impart thereto a waterrepellent finish, the improvement which consists of incorporating in the aqueous impregnating bath from 0.1 to 0.5 part by weight of nbutyl-methacrylate polymer resin for each part by weight of the stearamido-methyl pyridinium chloride.

ing of the polymers and interpolymers of vinyl Y 5. The process of producing upon textile fiber an improved water-repellent finish, which comprises impregnating the same with a carbontetrachloride solution of methylene-di(stearamido-methyl-thiocyanate) and n-butyl-methacrylate polymer, the polymer being employed in quantity not exceeding 0.5 part by weight for each part of said di-thiocyanate, then freeing the fiber from excess solvent and iurther subjecting the same to dry heat to develop the water-repellency eflect.

LUCIUS COLLINS. GEORGE ANTON SLOWINSKE. JOSEPH EDWARD SMITH. 

